Steam-boiler



(No Model.)

G.SBWELL. Steam Boiler.

.Patented March 29,1881.

Fig. 2

INVENTOB. Y. Wyk/0 Fig. 5

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GEORGE SEWELL, OF BRWOOKLYN, NEW YORK.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 239,348, dated March2:9, 1881. Application filed June 24, 180. (No model.)

'[0 all whom it may concern Be it known that I, GEORGE SEWELL, otBrooklyn, in `the county of Kings and State of New York, 'have inventeda new and useful Improvement in` Boilers or Steam-Generators, whichimprovement is fully set forth and illustrated in the followingspecitcation and accompanying drawings. l The object ot' this inventionis to simplify the construction of `boilers and steam-generators, and toso arrange their steam-generatin g surfaces that a maximum of suchsurface of the most efficient character may be obtained within any givenexterior lines or parallelopipedon circumscribing such surface. r

With this end in view the invention consists of a calorimeter plate orplates introduced into the furnace, in combination with verticalwater-tubes depending therein, said plate thus practically dividing thetube-space into two lines or compartments. v

The invention further consists in a certain method of securing saidtubes to theirtubesheet, whereby a thinner and` consequently betterheat-transmittin g sheet is caused to sustain in a durable andperfectlyltight condition the necessary number of tubes insertedtherein.

Vln the accompanyin g drawings, Figure l illustrates, in frontelevation, a boiler provided with myimprovements, as shown in theremaining gures. Fig. 2 is a median longitudinal vertical sectionthrough Fig. l. Fig. 8 is a plan ofthe calorimeter-plate, shown in partas an entire sheet, and in part as constructed in divisions or sections.Fig. et is an enlarged longitudinal section through one ot' the tubes ofthe "boiler, showing the method of connecting the tube, or an interposednipple or socket, to the tube-sheet. Fig. 5 is an enlarged sectionthrough one of the shorter tubes of the boiler, showing a method bywhich said tubes may be secured within the small length of spacenecessarily allotted to them.

The following is a description, in detail, of the construction andopera-tion of my invention, like letters of reference in the severaliigures ofthe drawings iudicatingthe same parts.

To the tube-sheet l), corresponding to the ordinary crown of the furnaceand forming the top of the furnace, are secured, in the mannerhereinafter described, the vertical water-tubes G. Within the space W,forming the exit for the gases of combustion, or entrance for the sameinto the uptake of the boiler, are placed the shorter tubes K. r

The calorimeter-plate A is introduced within the furnace B, preferablyat an inclination, as shown in the drawings, transversely to the lengthof the tubes G. The said plate, forming a perforated diaphragmsurrounding said tubes, is so cut around the tubes, as shown at O, and`at its sides, as shown at O, that a sufficient area of discharge isallowed for theproducts of combustion to. pass through the intervals Oand O, and through said intervals or spaces only. The velocity of thedraft, the consequent rate of combustion, and the calorimeter suited tothe attainment of these results under the most economic conditions, canby this means be very accurately regulated.

The calorimeter-plate A, instead of being made in one sheet, may be cutinto divisions orsections, as shown in Figs. 2 and 3, at the pointsindicated by the letters z" t'.

The tubes G are secured to the tube-sheet D` preferably by means of theinterposed nipple E. This arrangement allows of a comparatively thintube-sheet being used, thus securing a better heat-transmitting sheetthan it of thicker metal, while at the same time permitting the tube tobe unscrewed from the nippleV and removedor renewed, the nippleremaining in tight-fitting junction with the sheet. The nipple E isfirst screwed into the tubesheet D by means of screw-threads cut intoboth tube and sheet, and then the nipple is expanded and shouldered orbeaded respectively within and around the sheet D.

I am aware that it has been proposed to expand non-threaded smoothcylindrical tubes into helical-threaded holes in a tube-sheet; but I amnot aware that either tubes or nipples, previously threaded, have beenboth screwed and expanded into and around a correspondingpreviously-threaded tube-sheet, as herein4 described and claimed. If thehole in the tube-sheet be threaded, and the attempt be made to expand anon-threaded tube into said hole, unless the tube-sheet be ofconsiderable and undesirable thickness, the attempt will fail as apractical and useful operation, and in any case the practicability ofproperly IOO screwed into the end of the tube G.

expanding a non-threaded tube into a helicalthreaded hole would be avery uncertain and fortuitous operation at best, and the expanding-toolnecessary for the operation, if a practical device at all, would atleast require to be of exceptional accuracy and precision inconstruction and mode of application. I therefore confine my claim tothis part of my invention solely to the invent-ion set forth andembraced Within the narrow scope of claim 3.

Within the tube G is shown a strip of metal twisted into a helicoid andresting upon a plug rIhe object of this device is to create acomparatively quiescent center Within the tube G, in order that, as thecurrents of heated Water or steam bubbles ascend in the tube mostvigorously near 'its sides, there may be an axial returncurrent ofcooler water to the bottom of t-he tube, by which means total expulsionof the Water from the tube is prevented, as might otherwise happen underan excessively high temperature of furnace, particularly in tubes ofsmall diameter. Instead of this helicoidal strip of metal, a simpleinternal tube of lesser diameter than the tube G may be substituted.Said tube will be as eflicient in function as the helicoid h. But thesecirculating devices I do not claim as of my invention, and have onlyintroduced them herein as explanatory of the complete adaptation of myimprovements to such constructions as perform those functions inpractice desired in all good steam-generators.

As the great object of this invention is to obtain a maximum ofheating-surface vWithin given limits, and as the space W in the drawingsis valuablefor conversion into stea-mgenerating surface, and for suchpurpose is commonly unutilized, and therefore almost lost, I haveintroduced therein the short tubes K, VWhich largely utilize such spaceas a steamgenerating medium. As someingenuity of construction isrequired to properly insert said tubes into said space, I have shown inenlarged section in Fig. 5 a good method, and the best known to me, ofapplying the tubes K to the desired purpose.

By means of the screw-threads l on the end of the tube, and the couplingnut or socket shown thereon, and the shoulder or flange formed at theupper end of the tube, all clearly illustrated in Fig. 5, it is quiteobvious that by first screwing said socket upon the tube, then placingthe tube in position opposite its holes in the sheets, and thenunscrevving or backing off the socket a certain distance, the tube willbe practically clon gated, and rmly pressed and held Within and againstboth its top and bottom tube-sheet, any suitable cement, Washer, orjoint being interposed between the sheets and the iianges, respectively,of the tube and socket; but to this method of securing the tubes K, forthe reasons above given, I make no claim.

rIhe other portions of the boiler illustrated are those commonly used,the letter S indicating the furnace-door; J, a plug for emptying orcleaning the interior of the tubes G; c, the grate-bars, and a bars orgirders which brace or strengthen the tube-sheet D.

The arrows shown in Fig. 2 clearly indicate the courses of the currentsof the gases of combustion,and, with the explanations hereinabove given,no further description of the complete operation of the devicesconstituting` my said improvement in boilers is deemed necessary.

As of my invention I claim- 1. In a boiler or steam-generator, acalorimeter-plate, A, constructed as described, in combination withvertical Water-tubes G, depending from and secured to the top of thefurnace, substantially as and for the purposes set forth.

2. In a boiler or steam-generator, a calorimeter-plate, A, divided intosections, in combination with vertical Water-tubes G, depending from andsecured to the top of the furnace, substantially as and for the purposesset forth.

3. In combination with the tube-sheet of a boiler or steam-generator, atube or nipple screwed into said sheet by means of correspondingscrew-threads cut into both tube and sheet, said tube or nipple havingalso a circumferential bead or shoulder expanded thereon from Withinoutwardly and closely abutting the-inner side of the sheet,substantially as and for the purposes set forth.

GEORGE SEWELL.

Witnesses:

RICHARD E. SHAW, J or-nv L. BRooME, Jr.

